Consumers may have to wait years to get all the benefits of smart-meter technology.

Smart meters, which are replacing traditional power meters throughout Canterbury and in other parts of the country, have been criticised for delivering only higher power prices.

State-owned generator and retailer Meridian Energy and fully owned subsidiary Arc Innovations finished a $50 million installation of smart meters in about 110,000 Canterbury homes and businesses about six months ago.

They say the meters - developed, manufactured and monitored by Arc - have many benefits and are a big step forward from unsafe and ageing meters that had to be read at the property once a month.

But they also say the advantages will take years to be fully realised.

Former Meridian chief executive Keith Turner launched smart meters in August 2006, hailing them as "leading- edge technology" that would turn Christchurch into the "smartest city in the world".

Smart meters would "radically change the way electricity consumers buy and use their electricity" and would generate bills that would "always be accurate", he said then. But every week The Press receives complaints from consumers about the meters and the power price rises that appear to be associated with them.

Last year, Parliamentary Commissioner for the Environment Jan Wright called them "dumb meters" and recommended their introduction be stopped.

She said the meters did not contain the home area network (HAN) computer chip allowing consumers to use the meters to monitor power and use it more efficiently.

Meridian spokesman Alan Seay said it was taking longer than expected to bring all the smart-meter benefits to customers, but Wright's "dumb- meters" comments were "unfortunate".

"It was probably a bit over-sold, a bit of over-enthusiasm at the beginning, but it's a dumb reason to condemn this technology," he said. "What if we'd condemned cellphones because the old batteries lasted only half an hour?"

Arc chief executive Simon Clarke said it would make no sense to wait to introduce smart meters until there were genuinely "smart appliances" on the market for the meters to "talk to". At the moment there were no such appliances.

"The jury is still out on whether consumers want that or whether it's just a small sample who want that in-home display of their power consumption," he said.

"We took the view not to make a call on that until it becomes clearer."

The HAN chip could easily be added to the units later at no cost to customers, like the original units, he said.

"The customer has paid nothing. In every other jurisdiction in the world, you can pass the costs of doing this on to the consumer, but in New Zealand the full cost has been funded by Meridian."

Smart-meter installations had safety benefits but had also meant power price rises for some customers, Clarke said.

"The rollout has been a huge uplift in terms of the accuracy and safety of meter boards," he said. "We've gone into areas where old meter boards have been ticking time bombs in terms of fire risk and public safety.

"Smart meters have also copped the flak for old meters running slowly."

Seay said it was unfair for customers to blame smart meters for inaccurate readings and being on the wrong tariff.

"We are putting people on the right tariffs - 4000 of these people in the Orion network out of 110,000. These people had been undercharged because of that," he said.

"Because it has coincided with the rollout, people have linked it with the smart meters. These few anomalies that have been uncovered are no reason to condemn the whole new era of technology."

Arc employs 65 staff in Christchurch and provides meter services for customers of other power companies elsewhere in the country.